CHAPTER 4 : Climate NCERT SOLUTION CLASS 11TH Indian Physical Environment | EDUGROWN NOTES

SHORT ANSWER TYPE QUESTION:

Q1. What are the three important factors which influence the mechanism of Indian weather?
Answer
The three important factors which influence the mechanism of Indian weather are:• Distribution of air pressure and winds on the surface of the earth.
• Upper air circulation caused by factors controlling global weather and the inflow of different air masses and jet streams.
• Inflow of western cyclones generally known as disturbances during the winterseason and tropical depressions during the south-west monsoon period into India, creating weather conditions favourable to rainfall.

Q2. What is the Inter-Tropical Convergene Zone?
Answer
The Inter Tropical Convergence Zone (ITCZ) is a low pressure zone located at the equatorwhere trade winds converge, and so, it is a zone where air tends to ascend.
Q3. What is meant by ‘bursting of monsoon’? Name the place of India which gets the highest rainfall.
Answer
The sudden onset of the moisture-laden winds associated with violent thunder and lightening, is often termed as the “break” or “burst” of the monsoons.Mawsynram in Meghalaya is the place of India which gets the highest rainfall.
Q4. Define ‘climatic region’? What are the bases of Koeppen’s classification?
Answer
 A climatic region has a homogeneous climatic condition which is the result of a combination of factors. The bases of Koeppen’s classification are:• Temperature• Precipitation

Q5.Which type(s) of cyclones cause rainfall in north-western India during winter? Where do they originate?
Answer
Western cyclonic disturbances cause rainfall in north-western India during winter. They originate over the Mediterranean Sea.

Q6.Notwithstanding the broad climatic unity, the climate of India has many regional variations. Elaborate this statement giving suitable examples.
Answer
Due to the influence of monsoon, India as a whole has broad climatic unity. However, the climate of India has many regional variations expressed in the pattern of winds, temperature and rainfall, rhythm of seasons and the degree of wetness or dryness. There are various examples of this:
• Temperature: In the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh. Churu in Rajasthan may record a temperature of 50°C or more on a June day while the temperature in Tawang (Arunachal Pradesh) is 19°C on the same day.
• Rainfall: Cherrapunji and Mawsynram in the Khasi Hills of Meghalaya receive rain fallover 1,080 cm in a year while Jaisalmer in Rajasthan rarely gets more than 9 cm of rainfall during the same period.
• Monsoon: The Ganga delta and the coastal plains of Orissa are hit by strong rain-bearing stormsal most every third or fifth day in July and August while the Coromandal coast, a thousand km to the south, goes generally dry during these months. 
Q7.How many distinct seasons are found in India as per the Indian Meteorological Department? Discuss the weather conditions associated with any one season in detail.
Answer
The meteorological department recognise the following four seasons :(i) the cold weather season(ii) the hot weather season(iii) the southwest monsoon season(iv) the retreating monsoon season.
• The cold weather season: The cold weather season sets in by mid-November in northern India. December and January are the coldest months in the northern plain. The mean daily temperature remains below 21°C over most parts of northern India. The night temperature may be quite low.The Peninsular region of India, however, does not have any well-defined cold weather season. There is hardly any seasonal change in the distribution pattern of the temperature in coastal areas because of moderating influence of the sea and the proximity to equator.
During the winters, the weather in India is pleasant. The pleasant weather conditions, however, at intervals, get disturbed by shallow cyclonic depressions originating over the east Mediterranean Sea and travelling eastwards.
Winter monsoons do not cause rainfall as they move from land to the sea. It is because they have little humidity and due to anti cyclonic circulation on land. So, most parts of India do not have
rainfall in the winter season. However, there are some exceptions, Rainfall occurs in northwestern India due to western disturbances. Central parts of India and northern parts of southern peninsula also get winter rainfall occasionally.

Long Answer Type Questions:

Q1.Explain the important features of Winter Season of India.
Answer:
By October, the rainy season comes to an end all over the country and the days become short and the night become long. The rays of the sun are not overhead. The air turns cooler in the plains marking the coming of the winter season.

The winter season lasts from November to February every year. In the Northern Plains, very cold wind blow making the winter months severe. December and January are the coldest months in the northern plain. The mean daily temperature remains below 21°C over most parts of northern India.

Most of the hilly areas receive heavy snowfall. January is the coldest month in the Northern Plains. The winter season in Peninsular India is mild as a result of the influence of the surrounding water bodies. The coromandel Coast receives heavy rainfall during this season.

The desert is cool during the day but cold at night. The air starts warming up in the month of March, and the weather is neither cold nor hot. This time of early summer is also called the spring season. Every part of our country regularly experiences this cycle of seasons.

Q2.According to Koeppen, in how many groups- can you classify the climate of India?
Answer:
Koeppen identified a close relationship between the distribution of vegetation and climate. He selected certain values of temperature and precipitation and related them to the distribution of vegetation and used these values for classifying the climates. Koeppen introduced the use of capital and small letters to designate climatic groups and types. Koeppen recognised five major climatic groups, four of them are based on temperature and one on precipitation.

• Tropical climates,
• Dry climates,
• Warm temperate climates,
• Cool temperate climates,
• Ice climates

Classification of Indian climatic regions: Amw – Monsoon with short dry season.
Areas: West coast of India south of Goa
As – Monsoon with dry summer
Areas: Coromandel coast of Tamil Nadu
Aw – Tropical savannah.
Areas: Most of the Peninsular plateaus, south of the Tropic of Cancer
Bwhw – Semi-arid steppe climate.
Areas: North-western Gujarat, some parts of western Rajasthan and Punjab
Bwhw – Hot desert. Areas: Extreme western Rajasthan
Cwg – Monsoon with dry winter.
Areas: Ganga plain, eastern Rajasthan, northern Madhya Pradesh, most of North-east India
Dfc – Cold humid winter with short summer.
Areas: Arunachal Pradesh
E – Polar type. Areas: Jammu and Kashmir, Himachal Pradesh and Uttarakhand.

Q3.Explain the spatial variation in the rainfall throughout the country.
Answer:
There is great variation in rainfall throughout the country.

• While Cherrapunji and Mawsynram in the Khasi Hills of Meghalaya receive rainfall over 1,080 cm in a year, Jaisalmer in Rajasthan rarely gets more than 9 cm of rainfall during the same period.
• Tura situated in the Garo Hills of Meghalaya may receive an amount of rainfall in a single day which is equal to 10 years of rainfall at Jaisalmer. While the annual precipitation is less than 10 cm in the north-west Himalayas and the western deserts, it exceeds 400 cm in Meghalaya.
• The highest rainfall occurs along the west coast, on the western Ghats as well as in the sub-Himalayan areas in the north-west and the hills of Meghalaya, rainfall exceeding 200 cm. In some parts of Khasi and Jaintia hills, the rainfall exceeds 1,000 cm. In the Brahmaputra valley and the adjoining hills, the rainfall is less than 200 cm.
• Rainfall between 100-200 cm is received in southern parts of Gujarat, east Tamil Nadu, North-eastern Peninsular covering Orissa, Jharkhand, Bihar, eastern Madhya Pradesh, Northern Ganga Plain along the sub-Himalayas and the Cachar valley and Manipur.
• Western Uttar Pradesh, Delhi, Haryana, Punjab, Jammu and Kashmir, eastern Rajasthan, Gujarat and Deccan Plateau receive rainfall between 50-100 cm.

Q4.Explain the spatial variation in temperature in India.
Answer:
India has hot monsoonal climate which is the prevalent climate in south and south-east Asia.

• While in the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh.
• Churu in Rajasthan may record a temperature of 50°C or more on a June day while the mercury hardly touches 19°C in Tawang (Arunachal Pradesh) on the same day.
• On a December night, temperature in Drass (Jammu and Kashmir) may drop down to minus 45°C while Thiruvananthapuram or Chennai on the same night records 20°C or 22°C.
• In Kerala and in the Andaman Islands, the difference between day and night temperatures may be hardly seven or eight degree Celsius. But in the Thar desert, if the day temperature is around 50°C, at night, it may drop down considerably upto 15°-20°C.
• While snowfall occurs in the Himalayas, it only rains over the rest of the country. Similarly, variations are noticeable not only in the type of precipitation but also in its amount.

Q5.How economic life in India is affected by monsoon?
Answer:
Economic life of India is extremely affected by the monsoon.

• Monsoon is that axis around which revolves the entire agricultural cycle of India. Around 64 % people of India depend on agriculture for their livelihood and agriculture itself is based on south-west monsoon.
• Except Himalayas all the parts of the country have temperature above the threshold level to grow the crops or plants throughout the year.
• Regional variations in monsoon climate help in growing various types of crops.
• Variability of rainfall brings droughts or floods every year in some parts of the country.
• Agricultural property of India depends very much on timely and adequately distributed rainfall. If it fails, agriculture is adversely affected particularly in those regions where means of irrigation are not developed.
• Sudden monsoon burst creates problems of soil erosion over large areas in India.
• Winter rainfall by temperate cyclones in north India is highly beneficial for Rabi crops.
• Regional climatic variation in India is reflected in the vast variety of food, clothes and house types.

Q6.What is Global Warming? What are the effects of Global Warming?
Answer:
Due to global warming the polar ice caps and mountain glaciers would melt and the amount of water in the ocean would increase. It leads to rise in the sea level and melting of glaciers and sea-ice due to warming.

Effects:

• Sea level will rise 48 cm by the end of twenty first century.
• Increase the incidence of annual flooding.
• Insect-borne diseases like malaria, and leads to shift in climatic boundaries, making some regions wetter and other dries.
• Agricultural pattern would shift and human population as well as the ecosystem would experience change.
• The peninsular India would be submerged.
• Global warming refers to the increase in average ground temperatures refers to the increase in average ground temperatures on earth. These higher temperatures across the planet are caused by an intensification of the greenhouse effect.

Q7.What is Break in Monsoon? What are its causes? When is the monsoon expected to break in Kerala and reach the plains of Punjab?
Answer:
During the south-west monsoon period after having rains for a few days, if rain fails to occur for one or more weeks, it is known as break in the monsoon. These dry spells are quite common during the rainy season. These breaks in the different regions are due to different reasons:

• In northern India rains are likely to fail if the rain-bearing storms are not very frequent along the monsoon trough or the ITCZ over this region.
• Over the west coast the dry spells are associated with days when winds blow parallel to the coast.

Breaking of Monsoon:

• Breaking of the Monsoon in Kerala: Beginning of June.
• Reaching Punjab: First week of July.